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The purpose of the present study was to investigate the potential use of two PEGylated derivatives of rosin (PD) as sustained release film forming materials. The derivatives differed chemically by their acid numbers—PD-1 with 120.93; PD-2 with 88.19. The derivative films were characterized for surface morphology, water uptake-weight loss, angle of contact, water vapor transmission rate, mechanical properties; permeability study. Dissolution of diclofenac sodium (DS); propranolol hydrochloride (PHL) as model drugs was studied from coated pellets. The films of derivatives with; without plasticizers were smooth; continuous. PD-2 films developed greater numbers of pores when in contact with phosphate buffer pH 6.8. The low weight loss, low angles of contact; high water vapor transmission rate of PD-2 films were related to presence of higher concentration of PEG esters. Higher tensile strength; percent elongation of PD-2 films was due to greater degree of internal plasticization of the derivative. The permeability of films to model drugs propranolol hydrochloride; diclofenac sodium was inversely proportional to the film thickness; dibutyl phthalate concentration in them; the permeability being greatest in PD-2 films containing 10% PEG 200. Dissolution rate of propranolol hydrochloride was higher from the coated pellets. The dissolution data followed zero order, Baker–Lonsdale equation; Hixon–Crowell equation of release kinetics with high correlation coefficients. The mechanism of drug release from these coated systems however followed class II transport (n>1.0). The derivatives investigated could successfully retard release of the model drugs; offers an alternative to the conventionally used polymers.
V. S. Nde1Email:nandevs@rediffmail.com U. V. Barabde1 D. M. Morkhade1 S. B. Joshi1 A. T. Patil1
[1] Department of Pharmaceutical Sciences, Nagpur University Campus, Nagpur, 440 033, Maharashtra, India ;[2] Present address: Wockhardt Research Center, D-4 MIDC Area, Chikalthana, Aurangabad, 431 210, Maharashtra, India
2008,no15
The purpose of this study was to develop a dosage form that was easy to administer; provides rapid release of the drug roxithromycin, using modified polysaccharides as rapidly disintegrating excipients. Modified polysaccharides co grinded treated agar (C-TAG); co grinded treated guar gum (C-TGG) were prepared by subjecting pure polysaccharides namely agar; guar gum respectively to sequential processes of wetting, drying; co grinding with mannitol (1:1). The modified polysaccharides were characterized by Scanning Electron Microscopy; Diffuse Reflectance Spectroscopy; evaluated for particle size distribution, derived properties, swelling index; biodegradability. Optimization studies based on 2[2] factorial designs, with friability; disintegration time as response parameters were used to formulate orodispersible tablets of roxithromycin; evaluated for wetting time, water absorption ratio; in vitro drug release at salivary pH 6.4; physiological pH 7.4. Results indicated that lower levels of modified polysaccharides namely C-TAG in F3; C-TGG in F7; higher levels of microcrystalline cellulose, exhibited least disintegration times without friability concerns. In vitro release of optimized formulations F3; F7, both at salivary pH; physiological pH was found to be more than 90% within 30 min as compared to 27.82% at the same time point of conventional formulation. Stability studies carried out as per ICH Q1A guidelines suggested the formulations to be stable for a period of 6 months. Thus the approach of using modified polysaccharides as fast disintegrating excipient can be used to formulate a stable orodispersible formulation.
Vijay Sharma1 Anil K. Philip1 Kamla Pathak1 Email:kamla_rap@yahoo.co.in
[1] Department of Pharmaceutics, Rajiv Academy For Pharmacy, NH#2, Delhi–Mathura bypass, P. O. Chattikkara, Mathura, 281001, Uttar Pradesh, India
The aim of this study was to investigate the effect of Eudragit RS 30D, talc,; verapamil hydrochloride on dissolution; mechanical properties of beads coated with “drug-layered matrices”. This was accomplished with the aid of a three-factor multiple-level factorial design using percent drug release in 1; 2 h, T 50, tensile strength, brittleness, stiffness; toughness as the responses. Beads were coated in a fluidized-bed coating unit. Surface morphology; mechanical properties were evaluated by surface profilometry; texture analysis, respectively. No cracks, flaws; fissures were observed on the surfaces. The mechanical properties were dependent on the talc/polymer ratio. The release of verapamil from the beads was influenced by matrix components. Increasing the level of both talc; Eudragit decreased the percent drug released from 67% to 4.8%; from 80.7% to 6.7% in 1; 2 h, respectively,; increased T 50 from 0.8 to 25.7 h. It was concluded that beads could be efficiently coated with “drug-layered matrices”. The release of drug, however, depends on a balance between the levels of drug, talc,; polymer, whereby desired dissolution; mechanical properties could be controlled by the talc/polymer ratio; the level of drug loading.
Yasser El-Malah1 Sami Nazzal1 Email:nazzal@ulm.edu
[1] Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana 71209-0497, USA
The aim of this study was to investigate the possibility of using pectinate micro/nanoparticles as gene delivery systems. Pectinate micro/nanoparticles were produced by ionotropic gelation. Various factors were studied for their effects on the preparation of pectinate micro/nanoparticles: the pH of the pectin solution, the ratio of pectin to the cation, the concentration of pectin; the cation,; the type of cation (calcium ions, magnesium ions; manganese ions). After the preparation, the size; charge of the pectin micro/nanoparticles; their DNA incorporation efficiency were evaluated. The results showed that the particle sizes decreased with the decreased concentrations of pectin; cation. The type of cations affected the particle size. Sizes of calcium pectinate particles were larger than those of magnesium pectinate; manganese pectinate particles. The DNA loading efficiency showed that Ca-pectinate nanoparticles could entrap DNA up to 0.05 mg when the weight ratio of pectin:CaCl2:DNA was 0.2:1:0.05. However, Mg-pectinate could entrap only 0.01 mg DNA when the weight ratio of pectin:MgCl2:DNA was 1:100:0.01 The transfection efficiency of both Ca-pectinate; Mg-pectinate nanoparticles yielded relatively low levels of green fluorescent protein expression; low cytotoxicity in Huh7 cells. Given the negligible cytotoxic effects, these pectinate micro/nanoparticles can be considered as potential candidates for use as safe gene delivery carriers.
Praneet Opanasopit1 Email:praneet@email.pharm.su.ac.th Auayporn Apirakaramwong1 Tanasait Ngawhirunpat1 Theerasak Rojanarata1 Uracha Ruktanonchai2
[1] Nanotechnology for Drug/Gene Delivery Systems Group, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, Thailand ;[2] National Nanotechnology Center, Thailand Science Park, Pathumthani, Thailand
The aim of the present study was the evaluation of possible protective effects of quercetin and chrysin in experimental alloxan-induced diabetes in rats. Alloxan was injected at a single dose of 60 mg/kg (into the tail vein) for diabetes induction. Quercetin (50 and 100 mg/kg; orally) and chrysin (50 and 100 mg/kg; orally) were administered daily for 3 days prior and 7 days after alloxan injection. Alloxan induced a significant increase of glycaemia (p<0.001) in comparison with control animals. Quercetin at both doses prevented serum glucose elevation (p<0.001). However, the protective effect of chrysin was weaker and surprisingly, most prominent at the lower dose (p<0.05; p<0.01). On the other hand, glycosuria was increased in all groups of animals receiving alloxan. We suggest that the protective effect of the used flavonoids in experimental diabetes mellitus may be related to their antioxidative/chelatory properties. Increased glycosuria indicated that inhibition of renal glucose reabsorption may also play a role in the hypoglycaemic effect of both flavonoids.
Lukacinova, A. Mojzis, J. Benacka, R. Keller, J. Maguth, T. Kurila, P. Vasko, L. Racz, O. Nistiar, F.
Department of Physiology, Faculty of Medicine, Safarik University, Trieda SNP 1, 040 66 Kosice, Slovakia.
2008,no4
Morphological characteristics of peripheral blood cells, micronucleated erythrocyte counts and plasma biochemistry profile were examined in fourteen healthy captive Mauremys caspica and in twenty-three Mauremys rivulata. The size of erythrocyte cells were 19.07×11.68 micro m and 19.76×11.44 micro m for M. caspica and M. rivulata, respectively. Nucleus sizes were 6.50×5.30 micro m for M. caspica and 6.79×5.45 micro m for M. rivulata. The micronucleated erythrocyte (MNE) values were 0.0008 and 0.0037 for the males and females of M. caspica, respectively. The MNE values were 0.0002 for male and female M. rivulata. We found sex-dependent differences only in the Ca value in the blood biochemistry profile for healthy M. caspica. Sex-dependent differences were found only in albumin and P values in the blood biochemistry profile for healthy M. rivulata. No significant differences were found between males of both species in question with respect to plasma biochemistry values. However, only plasma total protein and Ca content levels differed significantly between the females of the two species.
Metin, K. Koca, YB Kral, FK Koca, S. Turkozan, O.
Department of Biology, Faculty of Science and Arts, Adnan Menderes University, 09010 Aydn, Turkey.
The effect of hormonal superovulation preparations of FSH (450 IU) or PMSG (1500 IU), on concentration of catecholamines (dopamine, norepinephrine and epinephrine) was studied in the oestrus period using radioenzymatic methods in the median eminence of the sheep. The administration of FSH caused a significant increase in the concentrations of norepinephrine (NE) and epinephrine (EPI) in the median eminence (ME) of sheep (p<0.01 and p<0.05, respectively). The comparison of the effect of hormonal preparations on the changes in catecholamine levels showed that the effect of FSH was observed mostly in eminentia mediana of sheep. We propose that the given changes in concentrations of catecholamines in the median eminence of sheep after administration of PMSG or FSH are related to steroids after hormonal stimulation.
Pastorova, B.
Department of Anatomy, Histology and Physiology, Institute of Physiology, University of Veterinary Medicine, Komenskeho 73, 041 81 Kosice, Slovakia.
Many physiological processes of domestic animals exhibit daily rhythmicity. The goal of the present study was to investigate the daily rhythms of calcium, inorganic phosphorus and 24,25-(OH)2-D3, 25-(OH)-D3 and 1,25-(OH)2-D3 in the blood serum of horses. Five Thoroughbred mares from the same farm, clinically healthy and placed in individual stalls, at the same environmental temperature and photoperiod were used. For 30 days prior to the study, the animals underwent the same pattern of daily activity. Blood samples were collected at 4 h-intervals for 48 consecutive h, starting at 08:00 h of the first day and finishing at 04:00 h of the second day, via intravenous cannula inserted into the jugular vein. Each individual sample was assessed for serum concentration of calcium and inorganic phosphorus by means of a UV spectrophotometric test, and serum concentration of 24, 25-(OH)-D3, 25-(OH)-D3, and 1,25-(OH)2-D3 were assessed by means of HPLC method. Data analysis was conducted by one-way repeated measures analysis of variance (ANOVA) and by the single cosinor method. ANOVA showed a significant effect of time on all the variables studied (p<0.0001) and post-hoc test (SNK) showed significant differences (p<0.001) comparing all the time intervals of 4 h, on either day. The application of the periodic model and the statistical analysis of the cosinor procedure allowed defining the periodic variables and their acrophases (expressed in hours) during the 2 days of monitoring. Calcium showed diurnal acrophases at 15:00 h for the 1st day and at 15:48 for the 2nd day; inorganic phosphorus showed diurnal coincident acrophases at 14:32 h both for the 1st and 2nd day and 25-(OH)-D3 showed diurnal acrophases at 14:08 h for the 1st day and at 15:04 h for the 2nd day. The results obtained could be useful for standardizing blood sampling according to the time of day and for optimizing the administration of these substances according to their circadian or other rhythms.
Piccione, G. Assenza, A. Fazio, F. Bergero, D. Caola, G.
Department of Experimental Science and Applied Biotechnology, Laboratory of Veterinary Chronophysioloey, Faculty of Veterinary Medicine University of Messina, Polo Universitario dell’Annunziata, 98168 Messina, Italy.
Alpha particle-emitting isotopes have been proposed as novel cytotoxic agents for augmenting targeted therapy. Properties of alpha particle radiation such as their limited range in tissue of a few cell diameters and their high linear energy transfer leading to dense radiation damage along each alpha track are promising in the treatment of cancer, especially when single cells or clusters of tumor cells are targeted. Actinium-225 (225 Ac) is an alpha particle-emitting radionuclide that generates 4 net alpha particle isotopes in a short decay chain to stable 209 Bi, and as such can be described as an alpha particle nanogenerator. This article reviews the literature pertaining to the research, development, and utilization of targeted 225 Ac to potently and specifically affect cancer.
Miederer,M Scheinberg,DA McDevitt,MR
Klinik und Poliklinik fur Nuklearmedizin, Klinikum rechts der Isar, Ismaningerstr. 22, Munchen, Germany.
2008,no4
Receptor-based radiopharmaceuticals are of great current interest in molecular imaging and radiotherapy of cancers, and provide a unique tool for target-specific delivery of radionuclides to the diseased tissues. In general, a target-specific radiopharmaceutical can be divided into four parts: targeting biomolecule (BM), pharmacokinetic modifying (PKM) linker, bifunctional coupling or chelating agent (BFC), and radionuclide. The targeting biomolecule serves as a carrier modify radiotracer excretion kinetics. BFC is needed for radiolabeling of biomolecules with a metallic radionuclide. Different radiometals have significant difference in their coordination chemistry, and require BFCs with different donor atoms and chelator frameworks. Since the radiometal chelate can have a significant impact on physical and biological properties of the target-specific radiopharmaceutical, its excretion kinetics can be altered by modifying the coordination environment with various chelators or coligand, if needed. This review will focus on the design of BFCs and their coordination chemistry with technetium, copper, gallium, indium, yttrium and lanthanide radiometals.
Liu,S
School of Health Sciences, Purdue University, West Lafayette, USA. lius@pharmacy.purdue.edu